Wisconsin Governor Scott Walker, fighting to win a second term, was buoyed by his state’s high court with victories upholding the Republican’s signature legislation on voter identification and union restrictions.

The Wisconsin Supreme Court rulings today come as Walker, sometimes mentioned as a possible 2016 U.S. presidential candidate, finds himself in a tight race with Democratic challenger Mary Burke to retain his current post.

A poll by Marquette Law School in Milwaukee earlier this month showed them in a statistical dead heat, with 46 percent of registered voters for Walker, and 45 percent supporting Burke, a former executive of the closely-held Trek Bicycle Corp. Among likely voters, Burke leads Walker 47 percent to 46 percent.

“This is clearly a good day for Walker,” said Charles Franklin, who ran the Marquette poll, in an interview. “This is the centerpiece of his campaign.”

The clear victory was on the union law. In a 5-2 ruling, the justices reversed a lower court decision that parts of the 2011 statute, known as Act 10, unduly burdened affected workers’ constitutional rights to free speech and free association. The law limits collective bargaining by public employees and deduction of union dues.

In two voter ID cases, the court also upheld Walker’s three-year-old photo identification law. Although the justices said the measure was allowable under the state constitution, the ruling was a hollow victory for Walker, as the ID law remains on hold because a federal court found it invalid. Walker is challenging that decision.

Two Victories

Still, Wisconsin remains one of 34 U.S. states to have some sort of voter identification law on the books, 31 of which are in force for this year’s midterm elections. Sixteen of the laws require a photo ID, according to the National Conference of State Legislatures.

Wisconsin’s primaries are scheduled for Aug. 12. General elections will be held on Nov. 4.

“Voter ID is a common sense reform that protects the integrity of our elections,” Walker’s office said today in a statement. “People need to have confidence in our electoral process and to know their vote has been properly counted.”

As for the decision on the public union law, Walker, 46, called it “a victory for hard-working taxpayers.”

One Wisconsin Now, a self-described progressive political advocacy group, called the court’s rulings “a supreme disgrace,” and an attack on both workers and voters.

Union Limits

“Today’s decisions don’t change the fact that this fall’s election is about jobs,” said Joe Zepecki, a spokesman for Walker’s Democratic challenger, said in an e-mail. “Under Scott Walker, Wisconsin is lagging behind on jobs, ranking dead last, 10th out of 10 in the Midwest in private sector job creation.”

The court said the public union legislation prohibits most, but not all, public employees from collectively bargaining on issues other than base wages, prevents municipal employers from deducting union dues from worker wages and requires unions to conduct annual recertification votes.

Wisconsin Supreme Court Justice Michael Gableman, writing for the majority, echoed a federal appeals court that previously upheld the union law as constitutional. Those decisions mark the end of viable legal challenges to the legislation, said attorney Lester Pines, a lawyer for union supporters.

“The lawsuits for the most part are done,” Pines conceded, adding that “anyone who thinks this is a death knell for municipal employee unions is wrong.”

Voter ID

Opponents of the voter ID law claim the restriction, similar to those pushed by Republican-dominated legislatures in the run-up to the 2012 presidential election, is intended to suppress the votes of those inclined to vote for Democrats.

They argue that lower-income and elderly voters, traditional constituencies for the party, are the most likely to lack identification required by such laws.

Justice Patience Drake Roggensack, writing for a 4-3 majority in the lawsuit filed by the Milwaukee chapter of the NAACP, said “voters who fear the legitimate ballots will be outweighed by fraudulent ones will feel disenfranchised.”

“The legislature can establish how, when and where voting occurs, but it cannot legislate who can vote,” said Pines, who in addition to representing unions in their case, argued on behalf of the League of Women Voters in the companion voter ID case.

“The law is not a voting qualification,” Kawski said. “It is not forbidden by the constitution.”

Justice N. Patrick Crooks dissented in the NAACP case, citing testimony that there’s been little or no evidence of voter-impersonation fraud.

“The photo identification requirements of the act would not prevent the types of voter fraud that have been uncovered during recent investigations,” Crooks wrote. He was joined in dissent by Justice Ann Walsh Bradley.

Chief Justice Shirley Abrahamson wrote a separate dissent in the NAACP case.

The fate of Wisconsin’s voter ID law now rests with the U.S. Court of Appeals in Chicago. The state has challenged a Milwaukee federal judge’s ruling April 29 that the measure illegally burdens the ability of minority citizens to exercise their right to vote.

Domestic Partnership

The justices did hand the Walker administration something of a defeat today, unanimously rejecting a challenge to the state’s domestic partnership law, which affords same-sex couples some of the same legal benefits as heterosexual married couples.

Those suing claimed the provision signed into law by former Governor Jim Doyle, a Democrat, was too similar to gay marriage, which is barred by the state’s constitution.